1. Field of the Invention
The present invention relates to a pressure sensitive sensor for detecting an external force by a housing elastically deformed by external pressure and electrodes provided in the housing contacting each other, and to a pressure sensitive sensor terminal processing method and manufacturing method.
2. Description of the Related Art
There are pressure sensitive sensors in which a plurality of electrodes made of metal plates, metal wires or the like are disposed within an elastically deformable housing so as to be spaced apart from one another. The housing is elastically deformed by pressure such that the plurality of electrodes contact one other, thereby causing electrical continuity, or a short-circuit, so that the pressure is detected.
In such a pressure sensitive sensor, terminal portions are open in order to be coupled to a connecting means, such as a cord, extending from a determination means such as a computer. Therefore, usually, the connecting means and the electrodes are coupled and then sealed to prevent malfunctioning resulting from, for example, entry of water. From the viewpoints of the reliability of the seal and work efficiency in the sealing operation, it is preferable that the seal used is formed by, for example, molding the terminal portions of the pressure sensitive sensor including the vicinity of the terminals of the connecting means with a synthetic resin material from the outside, in a state in which the terminals of the electrodes are connected to the connecting means.
However, when molding is carried out by using a synthetic resin material, while the connecting means and the electrodes are coupled, the terminal portions of the pressure sensitive sensor are put into the interior of a mold or the like. In this state, molten synthetic resin material is injected to effect molding as in the case of injection molding. Therefore, there is the possibility that the pressure applied during injection of the synthetic resin material will cause the electrodes exposed from the end portion of the housing to contact each other and make electrical continuity.
In addition, there is the possibility that during molding, the molten synthetic resin material will enter the spaces between the electrodes and such that dead zones are formed in places in the pressure sensitive sensor.
Due to these possibilities, it has been difficult to actually carry out terminal processing by molding.